Engine oil

[Jacko]

The way I see it, it's a bit like tyres.
Handbook for my '98 600 says use radial tyres of correct size,
now this doesn't stop me using the best tyres I can get as things have developed and improved in
the 15 years since my bike was made.

For oil it says use motor oil of a certain spec. Now if i meet this spec, great, if I surpass this with a super
oil of the 21st century then also great.

So meet the minimum and everything else is up to you.